1. Field of the Invention
The present disclosure relates to a control method of over-temperature protection, a driver chip, and a control system of over-temperature protection, particularly with regard to the driver chip for driving a high current DC fan, and the control method and system capable of controlling the output voltage to drive the DC fan to rotate at a full rotational speed, so as to prevent the driver chip from being overheated.
2. Description of the Related Art
When assembling electronic devices (such as computer hosts or barebones), a user can select different motherboards, CPUs, or different casings for combination, and even select any type of DC fans for cooling. Since efficiency of processors and memories are improved, it is foreseeable that power consumption and heat generation in operation of the component will continue to increase. In order to protect the components of the electronic devices from being damaged or destroyed because of the high temperature, user may choose a DC fan having a higher power for heat dissipation of the electronic device.
However, manufacturers of the motherboard or driver chip cannot predict a power value of the DC fan selected by the users, so they generally estimate a larger current value to encompass all possible current values of DC fans, for example, discrete metal oxide semiconductor field effect transistors (MOSFET) combined with driver chip and circuitry of DC fans. However, the manufacturers do not design protection circuits for the discrete MOSFET so that issues of overheating and burn-out often occur. If the over-temperature protection, over-current protection circuits and driving voltage amplification circuits are integrated in the driver chip, the driver chip can drive DC fans in most conditions, but still cannot drive the DC fans by a high current to have high heat dissipation.
Meanwhile, because of cost consideration, manufacturers are reluctant to increase the chip area for improvement in heat dissipation to meet the requirement of some high-current DC fans. Therefore, a control method of over-temperature protection, a driver chip, and a control system of over-temperature protection shall be designed, wherein shortcoming of prior arts are improved by the present disclosure. The integrated driver chip for DC fans is also adapted to large current DC fans, which enhances the practical application in the industry.